The Gero Cross is important to medieval art for the unique way it depicts Christ. The figure appears to be the earliest, and finest, of a number of life-size German wood sculpted crucifixions that appeared in the late Ottonian or early Romanesque period, later spreading to much of Europe. It is the first monumental depiction of the crucified Christ on the Cross and the first monumental sculpture dating from this period. Standing over six feet tall, it was one of the largest crosses of its time. Additionally, it appears to be the oldest Western depiction of a dead Christ on the cross; in most earlier depictions, Christ holds his head erect and looks straight ahead, or in some Carolingian examples looks down at the Virgin at the foot of the cross.

The shape of the Gero Cross is traditional to Carolingian religious art. However, this piece puts extra emphasis on the suffering of Jesus Christ's crucifixion, with the slumped head, lifeless body, and closed eyes. Other depictions are idealized and do not show Christ as vulnerable and disfigured. This was a major influence on later crosses, especially in 11th-century Germany, where you see more crosses that follow this rounded, natural style. The slumped head and twisted body, which arises as the hands are nailed to the cross at different heights, are found neither in Carolingian nor Byzantine art, and were to be slow to influence Western depictions, although the long hair spread over the shoulders is found in some Carolingian works. The style of the Gero Cross shows a great deal of Byzantine influence, most likely stemming from Otto II's marriage to a Byzantine princess, creating a cultural link between the Catholic Church and the Byzantine Empire. In crucifixions of the Gothic period, a still more slumped and curved figure of Christ, with knees bent sideways, was to become the standard depiction.

Earlier large figures of Christ on the Cross appear to have been in metal, or metal on a wooden core; there was said to be one in Charlemagne's Palatine Chapel in Aachen, and the Golden Madonna of Essen is an example of this type. The development of a tradition of free-standing monumental sculpture was a crucial development in Western art; in Byzantine art such images were and are avoided.

According to wikipedia